Doesn't anybody pinch the puppy?
I have sat and watched MANY a litter for hours and the puppy that is being bit doestn't just say "owee" and the other pup let's go, the pup that is being bit , BITES back!
There is a consequence for this behavior in my house. I am like a snake, a very quick pinch, even if the pup vocalizes when I do it.
For what it is worth I don't use an alpha roll. I am not a believer in them .